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When to Plant Watercress in Okmulgee County, OK

Okmulgee County, Oklahoma Zone 7b May

Your May planting checklist for Okmulgee County, Oklahoma

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Okmulgee County, Oklahoma.

Avg. last frost April 3
Avg. first frost November 2
Soil temp (4") 67°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Time to start watercress inside

    You're about 26 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Basket week: watercress

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

To set up a strong June, finish these tasks
  • First harvests: watercress

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Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.

Okmulgee County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is November 2, giving you a growing season of approximately 213 days.

At an elevation of 657 feet, Okmulgee County receives approximately 28.9 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Watercress during the growing season.

Okmulgee County, OK (Zone 7b) Long season
213 days
Last Spring Frost April 3
213 growing days
First Fall Frost November 2
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Okmulgee County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (139 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 6 – Jun 10
Recommended (50%) ✓ Fits season (136 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: May 15 – Jun 19
Safe Start (90%) ✓ Fits season (144 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 1

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Okmulgee County

How your county's soil matches Watercress's growing requirements.

Soil pH

Your soil pH (6.7–7.6) overlaps with Watercress's range (6.5–7.5), though not a perfect match.

Soil Texture

The loam soil in Okmulgee County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) — Watercress will thrive.

How to Plant Watercress

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Watercress

6
successive plantings in your 213-day season

Sow every 4.6 weeks. Last sowing by Sep 03 to harvest before frost.

For a dedicated fall crop, sow by Aug 24.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 2,116 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Watercress

Watercress needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Watercress Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 6.5" 3.5" 3" 💧 Light watering
May 6.5" 4.2" 2.3" 💧 Light watering
Jun 6.5" 4.6" 1.9" 💧 Light watering
Jul 6.5" 3.7" 2.8" 💧 Light watering
Aug 6.5" 3.3" 3.2" 💧 Light watering
Sep 6.5" 2.5" 4" 🚿 Regular watering
Oct 6.5" 1.7" 4.8" 🚿 Regular watering
Nov 6.5" 1" 5.5" 🚿 Regular watering
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Okmulgee County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Watercress Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Watercress needs ~912 GDD — county provides 3,887 GDD Excellent fit

Watercress Planting Timeline — Okmulgee County, OK

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Harvest May 15 May 15 – Jun 19
Fall Sowing August 24 Aug 24 – Sep 7

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July
August Fall Sowing
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

213 days in Okmulgee County

Growing Tips for Watercress in Okmulgee County

Direct sow Watercress outdoors after April 03 in Okmulgee County when soil has warmed and frost danger has passed.

Your generous 213.0-day season in Okmulgee County allows multiple plantings of Watercress. Sow every 20.0 days for continuous harvest.

Common pests for Watercress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watercress in Okmulgee County, OK?

Okmulgee County is in Zone 7b with an average last frost of April 3. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Okmulgee County, OK?

Okmulgee County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 3 and first fall frost is November 2.

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Your Okmulgee County Garden Planner — Free

A 24-page printable planner built for Okmulgee County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Okmulgee County, OK. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.